The inventive concept relates to a circuit and method for converting Boolean and arithmetic masks. More particularly, the inventive concept relates to a circuit and method for converting Boolean and arithmetic masks that reduce the overall number of logic gates and operate with greater speed.
A side-channel crypto-analysis approach, such as a differential power attack (DPA), can more efficiently obtain key information from a crypto system, as compared with conventional mathematical attacks. A masking method is one of the strongest methods of solving the DPA and conventionally uses Boolean and arithmetic masks.
The Boolean mask is a sequence pair (y, r) satisfying the relationship k=y^r with respect to an m-bit integer k, where “^” denotes an exclusive OR operation. The arithmetic mask is a sequence pair (x, r) satisfying the relationship k=x+r mod 2n with respect to the m-bit integer k.
A circuit may be used for converting the Boolean and arithmetic masks during a cryptographic process, but such circuits use many logic gates and are characterized by slow operating speeds.